I second that! And when you say Xilinx-boards I reckon you mean for example:
- Spartan 3E Starter Board 500E
- Spartan 3E Starter Board 1600E

of which at least the first is quite widely used among hobbyists.

Does the MinimigTG68 fit into a 500E, I'm not sure today..

The old: Spartan-3 Starter Kit (200K or 1000K) with it's 1 MB SRAM will probably
not be a good target I suppose.

I own one Spartan-3 Starter Kit 200K and one Spartan 3E Starter Board 1600E
which both work very well for lots of projects. I also have developed an
ArcadeExtender board which fits both and others (with some additional simple
soldering) and gives a good platform for Minimig and other similar projects and
makes the Xilinx boards more look/work like the Altera's with ALL their nice
connectors.

Arcade Extender
4096 colors, Simple Stereo Sound Output, 1 Digital Joystick (as used in
64/Amiga/ST), Extra PS/2 to host both Mouse/Keyboard, SD-Card SPI interface,
MIDI-in. I have 8 boards unpopulated and are willing to let them go for the
price they cost me to get done.. post me privately if interested. Without such a
board I think you need to extend the Xilinx-boards a lot to get something nice
out of it! Of course if you go for simple solution the FPGAArcade solder fix for
the VGA will al least fix Video in a very simple and cheap way
(http://www.fpgaarcade.com/displaytest.htm)

MinimigTG68 on Xilinx boards:
I would be able to put hours into such a project but I would probably also need
help . The biggest hurdle if I understand correctly is to get the DDR-controller
to work with the Minimig. And this is NOT my cup of tea for now.. There are
working DDR-controllers out there, but there always seem to give some
problems/inconsistencies when tried out.. somebody who knows otherwise?

Any more interested parties to this goal? There should be many people out there
who would like to see the Amiga come to life on their boards I think.

In the past I've fiddled around with many small projects for example a working
FPGA-64 with my setup including a working SID-chip in it! But the Amiga would be
even better!

For now I'm trying out a Multi-timbrel FPGA-MIDI-synthesizer built by another
Swedish FPGA-hacker which is very nice with it's included filtering-features and
up to 40 simultaneous voices split over max 2 Synthesizers!